ABSTRACT
The term “rhinencephalon” has its roots in the teratology of the early nineteenth century. Indeed, this term appears in the writings of the famous French naturalist, Etienne Geoffroy Saint-Hilaire, though its meaning was quite different from that of today. In his 1822 monograph on human monstrosities, the author termed “rhinencephalon” one of the thirteen kinds of acephaly characterized by tube-shaped nasal teguments and the total absence of an olfactory nervous system (1822, pp. 93–96). Therefore, a term which was later to designate that part of the nervous system responsible for olfaction initially denoted a dysgenesis distinguished, paradoxically, by the lack of an olfactory nervous system.
